Valvular Heart Disease

1
Valvular Heart Disease

• Stenosis - failure to open, preventing forward
  flow
• Regurgitation - failure to close, allowing
  reverse flow

2
Aortic Stenosis

• Postinflammatory scarring - RHD
• Senile calcific aortic stenosis
• Calcification of bicuspid valve

3
Aortic Regurgitation

• Postinflammatory scarring
• Syphilitic aortitis
• Ankylosing spondylitis
• Rheumatoid arthritis
• Marfans syndrome

4
Mitral Regurgitation

• Leaflet - postinflammatory scarring, infective
  endocarditis
• Tensor - rupture of papillary muscle or chordae
  tendineae
• Left ventricle - LV dilatation, calcification of
  mitral ring

5
Rheumatic Fever

• Systemic disease
• Polyarthritis of large joints
• Carditis
• Erythema marginatum of skin
• Subcutaneous nodules
• Sydenhams chorea

6
Rheumatic Fever Criteria

• Major - carditis, polyarthritis, chorea, erythema
  marginatum, subcutaneous nodules
• Minor - previous RHD, arthralgia, fever, elevated
  ESR, ECG changes

7
Rheumatic Fever Epidemiology

• RF correlated with duration and severity of
  pharyngitis and magnitude of host immune response
• Risk factors - cold climates, poor living
  conditions, inadequate medical care
• Mortality - 20.6/100,000 in 1940 and 2.2/100,000
  in 1982

8
RF Pathogenesis

• Heart valve glycoproteins cross-react with
  hyaluronate capsule of strep
• Cross reactivity between cardiac muscle and strep
  cell wall M proteins
• Cytotoxic T cells sensitized to strep antigens
  lyse heart cells
• Immunoglobulins and complement attach to cardiac
  myocytes and Aschoff nodules

9
RHD Morphology

• Aschoff nodule - fibrinoid necrosis, cardiac
  histiocytes, plasma cells, lymphocytes and
  neutrophils
• Perivascular or subendocardial interstitial
  connective tissue
• Rarely subepicardium or heart valves
• Healed lesion shows fibrosis

10
Aschoff nodule in rheumatic heart disease
11
Aschoff nodule in rheumatic heart disease. These
are often in perivascular connective tissue
rather than the myocardium.
12
Aschoff nodule in rheumatic heart disease. Area
of fibrinoid necrosis in center.
13
Subendocardial Aschoff nodule in rheumatic heart
disease.
14
RHD Manifestations

• Pericarditis - diffuse inflammatory reaction
  Myocarditis - interstitial connective tissue
• Endocarditis - mitral valve 40-50, aortic valve
  15-20, mitral and aortic valves 35-40, mitral,
  aortic and tricuspid valves 2-3
• Verrucae along lines of closure of leaflets with
  fibrinoid necrosis and fibrosis

15
Rheumatic pericarditis a diffuse fibrinous
exudate on the epicardial surface.
16
Mitral rheumatic heart disease. Verrucae along
lines of closure and thickened chordae
tendineae.
17
Mitral rheumatic heart disease. Verrucae along
lines of closure and thickened chordae
tendineae.
18
Mitral and aortic rheumatic heart disease.
Verrucae along lines of closure and thickened
chordae tendineae.
19
Fish-mouth deformity of mitral valve in
rheumatic disease.
20
Aortic rheumatic heart disease. Verrucae along
lines of closure. The valve is fibrotic and
stiff.
21
Infective Endocarditis

• Site of Involvement - mitral valve 25-30, aortic
  valve 25-35, tricuspid valve 10, valve
  prosthesis 10, congenital defect 10
• Friable vegetations containing RBCs, fibrin,
  inflammatory cells and organisms

22
Acute Infective Endocarditis

• Causative agent - Staph. aureus
• Usually normal hearts or previous surgery
• Metastatic foci of infection common
• Symptoms - high fever and emboli
• Mortality - as high as 70
• Associated with chronic alcoholism, drug
  addiction, immunodeficiency

23
Aortic valve acute endocarditis. This would be
caused by Staph or other bacteria. Mitral valve
is normal.
24
Aortic valve acute endocarditis.
25
Aortic valve acute endocarditis.
26
Aortic valve acute endocarditis. The probe
extends through a perforated leaflet. Acute
endocarditis is very destructive of the valves
and often embolizes too.
27
Mitral valve acute endocarditis.
28
Mitral valve acute endocarditis.
29
Microscopic image of acute infectious
endocarditis. Many bacteria (S. aureus) are
present near the top, and many neutrophils are
present near the bottom.
30
Subacute Infective Endocarditis

• Causative agent - Strep viridans
• Hearts with underlying cardiac disease
• Metastatic foci of infection is rare
• Symptoms - progressive weakness, fever, night
  sweats, anemia, weight loss
• Mortality 10-40
• Difficult to diagnose

31
Subacute bacterial endocarditis on mitral valve.
32
Subacute bacterial endocarditis on mitral valve.
Thickened chordae tendineae mean the patient
probably had rheumatic valve disease, then got
infectious endocarditis on the damaged valve.
33
Aortic valve subacute endocarditis.
34
Mitral valve subacute endocarditis.
35
Microscopy of subacute bacterial endocarditis.
Neutrophils, but no organisms are seen in this
field.
36
Microscopy of subacute bacterial endocarditis.
Rare organisms are seen in this field.
37
Microscopy of subacute bacterial endocarditis.
Large clumps of small cocci (presumed Streptococci
) are seen in this field.
38
High power microscopy of subacute bacterial
endocarditis. Large clumps of small cocci
(presumed Streptococci) are seen in this field.
39
Infective Endocarditis

• Cardiac complications - coronary artery
  embolization, abscess formation, erosion or
  perforation of valve or chordae tendineae
• Non-cardiac complications - septic emboli, immune
  complex deposits in vessels or kidneys

40
Nonbacterial Thrombotic Endocarditis

• Morphology - sterile small vegetations with
  fibrin and platelets along closure lines of
  aortic and mitral valves
• Clinical significance - hypercoaguable states and
  may become infected or source of emboli

41
Aortic valve nonbacterial thrombotic endocarditis.
42
Mitral valve nonbacterial thrombotic endocarditis.
43
Mitral valve nonbacterial thrombotic endocarditis.
44
Microscopy of nonbacterial thrombotic
endocarditis. There is fibrin and there can
be some fibroblasts, but there are no neutrophils
and no bacteria.
45
Nonbacterial Verrucous Endocarditis (Libman-Sacks)

• Mitral and tricuspid valvulitis in SLE
• Mucoid pooling, fibrinoid necrosis and fibrosis
  within connective tissue of valves

46
(No Transcript)
47
Lupus patient with Libman-Sacks nonbacterial
endocarditis of the mitral valve.
48
Lupus patient with Libman-Sacks nonbacterial
endocarditis of the mitral valve.
49
Lupus patient with Libman-Sacks nonbacterial
endocarditis of the mitral valve.
50
Calcific Aortic Valve Stenosis

• Pathogenesis - post infective endocarditis or
  rheumatic fever
• Common in congenital bicuspid valves or normal
  valves of elderly people
• Morphology - fibrosis and calcification that
  obliterate sinuses of Valsalva and valve leaflets
• Clinical significance - pressure overload left
  ventricle

51
Above left, a normal aortic valve. To right,
two calcific tricuspid aortic valves. The
fibrosis calcification that extends to the
edges of the leaflets in the valve at bottom,
causing stenosis.
52
Congenital bicuspid aortic valve. These are very
prone to develop calcific aortic stenosis.
53
Calcific aortic valve stenosis.
54
Microscopy of calcific aortic valve stenosis,
with fibrosis and calcification (the very
dark pink material was calcified). There is no
inflammation and there are no organisms.
55
Microscopy of calcific aortic valve stenosis,
with fibrosis and calcification (the very
pale blue material was calcified). There is no
inflammation and there are no organisms.
56
Calcification of Mitral Valve Annulus

• Morphology - irregular stony hard beading in the
  mitral valve annulus, often associated with
  ischemic heart disease
• Clinical significance - may narrow valve lumen
  and impinge of conduction system

57
Mitral Valve Prolapse

• Morphology - excessively large leaflets, long
  chordae tendineae, or myxomatous change within
  valve leaflets especially posterior leaflet
• Etiology - unknown, hereditary, Marfans
• Clinical significance 5-7 of general
  population, mostly women, susceptible to
  endocarditis and psychiatric disorders

58
Mitral valve prolapse (the large valve at the
left). The valves and chordae are too long.
59
Mitral valve prolapse. The valves and chordae are
too long.
60
At left, a normal mitral valve. At right, myxoid
degeneration. This happens when there is
turbulent flow, such as through a mitral valve
with prolapse.
61
Complications of Artificial Valves

• Thrombosis / thromboembolism
• Anticoagulant related hemorrhage
• Infective endocarditis
• Structural or biological deterioration
• Nonstructural dysfunction - tissue entrapment,
  paravalvular leaks, anemia

62
Porcine valve. Top leaflet has deteriorated and
is essentially destroyed.
63
Porcine valve. Thrombus on leaflets to right (the
red-brown material from 2 to 6 o'clock).
64
Porcine valve. Top leaflet has torn loose focally
(at arrow).
65
Ball cage mechanical mitral valve with fibrin
and hemorrhage around it. Extensive clot can
block blood flow or even embolize.
66
Prosthetic valve with extensive fibrin thrombus.